A patentability search was conducted prior to the preparation of this application and this search brings to light the following patents as those found coming closest to the present subject:
______________________________________ 1,493,584 Wills 3,692,244 Lincoln 2,259,215 Scheurer 3,942,724 Mocarski 2,820,418 Sullivan et al. 3,515,354 Presson 1,469,479 Kent 3,575,352 Hall 298,449 McOvat 3,471,091 Baker ______________________________________
A brief comment is made on the more pertinent of these references as follows:
Sullivan et al.
This patent discloses a jet assembly for pumps comprising a nozzle and venturi. The nozzle is shown at 36 and the venturi at 12. This patent is clearly lacking in the cloverleaf passage through the throat of the venturi and which has lateral extensions or recesses which are helical, as in the present invention. It is also lacking in the hydro-step which results in the mist being formed into fine droplets.
Presson
This patent is to a spray nozzle used in applying wall texturing materials to wall structures. This is a far cry from generating a fine mist and the device illustrated clearly does not have the cloverleaf passages with the helical lateral extensions or recesses or hydro-step of the subject spray nozzle.
Scheurer
This patent is to a spray gun for applying heavy liquid material such as emulsified asphalt loaded with cork to the walls of a structure. Here again, it is noted that the intended use of the spray gun is far removed from that of the instant spray nozzle and, in addition to lacking the features discussed above, fails to disclose a complete venturi.
Wills
This reference is to an oil burner and is cited because of the disclosure in FIG. 4 of the spiral grooves 18. However, they are not included in the throat of a venturi if indeed a venturi is disclosed.
Kent
This is another example of a burner and is cited because it discloses the spiral grooves 19 in the inner surface of the inlet of a venturi. However, it is also lacking in the cloverleaf passage and hydro-step of the subject now under consideration.
No comment is made on the remaining patents other than to point out that they are cited to complete the picture of the art of spray nozzles and devices generally similar thereto.
The prior art as exemplified by the above patents is noticeably lacking in a spray nozzle comprising a body that has a generally cylindrical contour and is formed with an axial venturi passage including an upper flared portion, an intermediate throat or waist, and a lower bell-shaped portion. The venturi passage is cloverleaf in horizontal cross-section and has helical lateral recesses or extensions. The bell-shaped lower portion is formed with a hydro-step over which the thin-walled tubular sheet of water passes to be broken up into a mist or fine droplets. A stream of water is introduced into the upper flared portion and a conduit for air under pressure has a portion adjacent to its discharge end coaxial with the venturi passage.